Plot Synopsis

PLANET EARTH: MISSION GALAPAGOS is a three-part documentary series that follows Liz Bonnin and a team of world-renowned scientists, who assemble for Mission Galapagos, one of the most ambitious scientific expeditions ever attempted in this remote archipelago. Located on the equator, it's a spectacular archipelago where evolution has proceeded at an extraordinary pace. But these islands are changing and this tropical paradise is under threat as our climate changes faster than ever before.

In the first episode, "Cauldron of Life," Liz joins a scientific team aboard the research vessel the Alucia on an expedition across the Galapagos Archipelago. The journey begins on the Galapagos' west side at the youngest and most volcanically active islands in the archipelago, Isabela and Fernandina, home to a richly diverse wildlife scene. Here, Liz and the team journey into the clouds above 'Wolf', the tallest volcano in the Galapagos, where they join a group of biologists hunting for the rarest of species: the elusive and bizarre pink iguana, which teeters on the edge of extinction. But how and why did it come to live on the top of a volcano? Back on the research vessel, Liz boards Alucia's Triton submersible to descend a kilometer, the deepest anyone has ever dived on the Galapagos Islands, into the ocean abyss in search of a new species hiding in the darkness. Liz also travels to one of the most remote locations in the Galapagos, Alcedo Volcano, in search of the largest population of giant tortoises. Plagued by drought in recent months, scientists are keen to find out how this prehistoric species has fared. Finally, Liz helps out with a ground-breaking science experiment to x-ray marine iguanas that have so far stunned the scientific community with a new mutation. As with all life on these remote islands, the key to survival is adaptation.

Then, in "Secrets of the Deep," Liz and a team of scientific experts set off beneath the waves to explore this spectacular archipelago. It's an exciting opportunity to delve into a world that largely remains a mystery to science. Venturing down in the Nadir, a specially equipped deep sea submersible, Liz goes in search of an elusive ocean giant, the mola or sunfish, to understand more about its little-known behaviour in the deep. En-route back to the research vessel Alucia, Liz checks in on a playful sea lion population to see how they have been affected by a recent extreme weather event, El Nino. Back on board the Alucia the team set sail north for the most remote and inhospitable islands in the Galapagos - Wolf and Darwin. Here, Liz joins a team tagging and tracking Hammerhead sharks (who school at this location in huge numbers) as they attempt to unlock the secrets of the sharks' stunning behavior. But nothing can prepare the Alucia crew for the power of the ocean in this isolated marine wonderland.

In the finale, Liz and a team of scientific experts journey south to visit the oldest islands in the Galapagos, to see first-hand the impact that humans have had on this pristine wilderness. Back on the larger island of Isabela, where her journey first began, Liz descends into a spectacular vertical lava cave. Deep inside, she discovers how this hidden world might even provide an answer to how it might be possible to inhabit other planets. On her last land-based stop on Santa Cruz, Liz comes face to face with the effects of man when she explores the magical misty Scalesia forests and meets scientists that are tracking the invasive species spreading throughout the islands. It's here that she also checks in on a giant tortoise population, whose ancient migration pathways have come under threat from the largest human population on the archipelago, and meets a man on a mission to protect this iconic creature. Finally, Liz dives into the deep blue waters to witness the birth of a brand new island: this is how it all began. Coming full circle, Liz and the team are able to reflect on the importance of their missions, which will help to protect the Galapagos and its extraordinary wildlife in the future. In an ever-changing world, what we learn now from these incredible living natural wonders and what we can pass on to future generations has never been more important.

This series, airing as PLANET EARTH: MISSION GALAPAGOS, had its U.S. premiere on Saturday, August 25, 2018 at 9pm ET/PT on BBC America.